I'm using Maven as POM. I was missing one configuration file whene loading my unit tests that was required at runtime and here's the output I got when running maven, and maven -X test:

BUILD FAILED
File...... /home/aabdelaziz/.maven/cache/maven-multiproject-plugin-1.3.1/plugin.jelly
Element... maven:reactor
Line...... 217
Column.... 9
Unable to obtain goal [multiproject:install-callback] -- /home/aabdelaziz/.maven/cache/maven-test-plugin-1.6.2/plugin.jelly:133:41: java.lang.NoClassDefFoundError

WOW it is very expressive Error Message.

after searching the web for solution for this problem. I found the solution which is magic line I should add to my project.properties file.
This is the line
maven.junit.fork=true.